Zelensky is seen in his office in Kyiv for the first time since invasion began.

President Volodymyr Zelensky of Ukraine spoke from his office in Kyiv on Monday night, the first time he had been seen there since the Russian invasion began on Feb. 24.

In a brief video posted on his Facebook page, Mr. Zelensky said that he was not hiding, and he was not afraid of anyone.

“We used to say: Monday is a hard day,” he said. “There is a war in the country so every day is Monday, and now we are used to the fact that every day and every night are like that.”

In the video, Mr. Zelensky provided updates on Russian attacks, and also said he had signed a decree on Monday to present state awards to 96 “Ukrainian heroes.”

Mr. Zelensky also criticized Russian troops for attacks on certain sites on Monday, including accusing them of firing at a bread factory in Makariv, about an hour west of Kyiv.

“Think about it — to fire at the bread factory. Who should you be to do that?” Mr. Zelensky said.

The president also condemned Russian troops for disregarding an agreement on a humanitarian corridor, after shelling prevented evacuation of besieged cities.

“Did it work?” Mr. Zelensky said of the corridor. “Russian tanks worked instead.”

In an update on Monday night, Britain’s defense ministry said that Russian troops continued to directly target evacuation corridors, which had resulted in several casualties of civilians who tried to flee Irpin, just outside Kyiv. It said the town had been without heat, water or power for several days because of fighting in the area.

Mr. Zelensky’s nightly video addresses, rallying Ukrainian resistance and world opinion, have become something of a ritual since Russia invaded on Feb. 24. Russian offensives against several major cities have bogged down in the face of logistical problems and unexpectedly fierce defenses.

In his Monday night message, Mr. Zelensky said that a national movement had unfolded in the southern part of the country, creating “a nightmare” for Russia.

“We are not afraid of tanks and machine guns,” he said.

Mr. Zelensky said that every day of resistance puts Ukraine in a “strong position” to guarantee the country’s future, adding that Ukraine will rebuild everything that has been shelled and bombed by Russian forces.

“There will be no trace of the enemy,” he said. “We will make our cities destroyed by the invader better than any city in Russia.”